Understanding Duty Cycle Before You Buy An Inverter Welder

Every workshop is different, so rather than relying on general advice, it's worth getting your own set-up properly assessed. A system that works well for one shop can be quite wrong for another with different ventilation, floor space or process mix, and an on-torch extraction option, such as those available for Fronius torches, suits a different layout to a fixed overhead hood.

The collet and collet body hold the tungsten in place and need to match its diameter exactly. A worn or incorrectly sized collet allows the tungsten to shift slightly during welding, which affects arc stability in ways that are easy to blame on technique when the actual cause is a consumable that needs replacing. CK Worldwide and Furick are two of the ranges we stock here, and these are inexpensive parts, but neglected ones cause a disproportionate amount of frustration at the torch.

Duty cycle is one of the most misunderstood figures on a welder's spec sheet, yet it tells you more about real-world usability than the headline amperage does. It's expressed as a percentage over a ten-minute period at a given output, so a machine rated at 30% duty cycle at its maximum amperage can run for three minutes out of every ten at that setting before it needs to rest and cool.

Welding produces fume made up of fine particulates and gases, and the composition varies depending on the process, the filler material and any coatings on the base metal. Fume rises from the arc and, without adequate control, can build up in the breathing zone of anyone working nearby, which is why extraction is treated as a core part of workshop set-up rather than an optional extra.

A reliable, adequately sized compressed air supply is the part most first-time buyers underestimate. Undersized or contaminated air, whether from moisture, Tec Products Ltd oil or an undersized compressor, is one of the most common causes of poor cut quality and shortened consumable life, so it's worth checking a machine's air requirements against what your compressor can actually deliver before you buy, not after.

Plasma cutting uses a jet of ionised gas, usually compressed air, forced through a nozzle at high speed and heated by an electric arc to a temperature hot enough to melt through electrically conductive metal. The molten material is then blown clear by the same jet, leaving a narrow, clean cut. Unlike oxy-fuel cutting, plasma works on any conductive metal, including stainless steel and aluminium, not just carbon steel. Hypertherm is the plasma cutting brand we get asked about most, and it's worth understanding the basics before comparing specific units.